Polymer Chain Mobility under Shear—A Rheo-NMR Investigation
AbstractThe local dynamics in polymer melts and the impact of external shear in a Couette geometry have been investigated using rheological nuclear magnetic resonance (NMR). The spin-spin relaxation time, T2, which is sensitive to chain-segment motion, has been measured as a function of shear rate for two samples of poly(dimethylsiloxane). For the low-molecular-weight sample, a mono-exponential decay is observed, which becomes slightly faster with shear, indicating restrictions of the polymer chain motion. For the high-weight sample, a much faster bi-exponential decay is observed, indicative of entanglements. Both components in this decay become longer with shear. This implies that the free polymer segments between entanglements become effectively longer as a result of shear. View Full-Text
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Wiesner, B.; Kohn, B.; Mende, M.; Scheler, U. Polymer Chain Mobility under Shear—A Rheo-NMR Investigation. Polymers 2018, 10, 1231.
Wiesner B, Kohn B, Mende M, Scheler U. Polymer Chain Mobility under Shear—A Rheo-NMR Investigation. Polymers. 2018; 10(11):1231.Chicago/Turabian Style
Wiesner, Brigitte; Kohn, Benjamin; Mende, Mandy; Scheler, Ulrich. 2018. "Polymer Chain Mobility under Shear—A Rheo-NMR Investigation." Polymers 10, no. 11: 1231.
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